


The Edge of the Earth

by orphan_account



Category: Supernatural
Genre: Alternate Universe, Angst, Gen, Hunter Dean Winchester, Hunter Sam Winchester, M/M, Merman Castiel, Merpeople
Language: English
Status: Completed
Published: 2016-03-30
Updated: 2016-03-30
Packaged: 2018-05-29 23:18:21
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 1
Words: 9,512
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6398278
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: <blockquote class="userstuff">
              <p>The Winchesters are investigating a case involving missing people and legends of the sea. When Dean falls into the water and Sam can't save him, Castiel makes a decision that will change his life forever.</p>
            </blockquote>





	The Edge of the Earth

**Author's Note:**

> This fic for the Destiel Reverse Bang 2016 was inspired by the gorgeous art prompt submitted by Padaleckhi, who has been a fantastically supportive and enthusiastic partner, and can be found on tumblr here :http://padaleckhi.tumblr.com/ where you can also see all the art to go with the story.
> 
> Huge thanks to a couple of friends who dragged me through the quicksand when I was ready to sink:
> 
> yopumpkinhead, for catching all my ideas when I threw them at you in the very beginning and ironing out all my creases at the very end [and everything in between]. You are an all-round awesomeasaurus.
> 
> A_Diamond for the endless moral support, advice on all things, crackfic recs and writing parties; this would never have got finished without you!
> 
> All remaining mistakes are entirely my own.

******************************************** 

Dean guided the Impala carefully, not-so-silently cursing the cryptic instructions Sam had managed to find to get them to the small beach off Highway One. He hoped California's Pacific coast in November wouldn't have too many tourists as the crazy one lane dirt track didn't allow for much manoeuvrability.

 

"So there was nothing?" Dean prompted, turning off the ignition now he had pulled up.

 

"Nothing apart from the kayak," Sam answered, folding the paper and resting it on his lap.

 

The story that had been reported in the Herald detailed the air and sea search that had been carried out for two missing bird watchers. Their family alerted the coastguard after Laura and Justin Evans missed a family dinner and couldn't be reached at home. An upturned tandem kayak had washed up in a small cove a few miles down from where the couple had parked their car, and the search was called off.

 

Sam had been armed, his research done on potential non-natural causes and already had the fact that it was the third such case in as many months queued up should he need to try and sell it to Dean. After a few restful days that had turned into restless weeks, his brother didn't need much persuading as to why it had beaconed as a potential case.

 

The beach was a short hike away, the unfamiliar route commanding most of their attention. A blanket of seasonal fog wrapped the coastline. Navigating it with visibility being so limited wasn't the stupidest thing they had ever done, but it was certainly up there. The flashlights Dean had pulled from the trunk of the Impala were almost useless.

 

As they got closer to the sand, the fog continued to veil the view.

 

"Sam?" Dean checked, waiting for his brother's reply to judge the distance between them. "You good?"

 

"Yeah," Sam confirmed, his response met by the sound of falling rocks.

 

"Dean? DEAN!!!" Sam screamed.

* 

Dean heard nothing except for the thrashing waves as he hit the water. He registered that it was colder than he expected it to be, and this countered the shock of the fall, helping him to process that he needed to swim. Dean kicked towards the surface, using his hands to pull through. As he broke the surf, breathing hard, Dean struggled to fill his lungs.

 

"SAM!!!!!" he managed to shout before being dragged back under. Dean fought, lashing out but not getting free. He couldn't see what was forcing him down. Panic began to rise as he got lower. As he lost consciousness, Dean thought he saw something moving towards him.

* 

It wasn't that Castiel drifted; he knew his place amongst his brethren. Castiel's thoughts travelled when he rested, mapping out the whole of the sea with the stars. He wondered who had created the world above and why. The sky was peaceful. The sea was home. Why would the land and its people be created to cause destruction?

 

Duty-bound until death to protect their people from humankind, mermen had divided the seas into garrisons, and then stationed their warriors at outposts. Castiel had attacked his leader.

 

He had been getting indulgent, moving further into shallow waters than his responsibilities required. Zachariah had never fully trusted Castiel. Their alliance was purely tactical. Castiel yielded to the hierarchical order of authority, and Zachariah was unshakeable in his mission to defend by hurting those who had hurt.

 

Castiel had seen the struggle when Zachariah had first pulled the man under. He had known that he should fight alongside his kin and not against, but he had never seen a human this close before. The man was struggling, wild-eyed and desperate. Castiel recognised the same look on creatures trapped in nets, unable to comprehend but frantic with the need to escape. Zachariah's vengeful sneer as he pulled the man further towards the dark waters ignited something within Castiel.

 

He knew that he needed to block Zachariah from communicating with him. Castiel needed to close his mind to the telepathic language used by his kind. The network allowed merpeople to share their thoughts, but not their feelings. To maintain discipline and defence, the elders had cast a spell on all members of the clan. Pain caused between kin would not be tolerated. Any attack he made on another merman would be a silent scream in Castiel's own body.

 

He raced towards them, untying the flint knife from the strap around his waist and focused wholly on Zachariah. He gripped his knife and went for Zachariah's shoulder, wanting to subdue but not kill. Castiel was surprised that he got a clear jab as the blade pierced the skin. It was enough to lessen the merman's grip on the human, but Zachariah recovered from the initial shock too quickly. Face contorted with rage, he bucked his tail at Castiel, jostling him away. Zachariah was still clinging to his prize when Castiel took aim again, this time barely grazing him. Zachariah snarled in threat, daring Castiel to continue.

 

He launched himself at Zachariah's waist, using all his weight in an attempt to dislodge him. Zachariah crumpled forwards, bending at the impact. Castiel drove the knife deep into his other shoulder, twisting the blade hard. The combination of Castiel's efforts was enough for Zachariah to let go. Castiel tore his knife from the other merman's flesh, and used his tail to give a final push against Zachariah, sending him spiralling away.

 

Re-securing his weapon, Castiel couldn't stop to recover. He surged towards the man and reached out to stop him sinking further. He circled both arms underneath those of the human, gripped tight, and raised him to the surface.

 

As they broke through the water, Castiel realised something was wrong. There was no sign of life. He had expected a struggle as the man woke up, but he remained still. Castiel pulled him to the edge of the caves, stopping at a flat sloping rock.

 

Easing the man gently onto its surface, Castiel waited, not knowing what to do. Tentatively, he skimmed a finger over the man's lips, gently pressing to separate them. A fractured breath should have warned Castiel to retreat. He stayed in place and watched, hand now hovering his knife, a precaution without intent. Knowing what it could mean but wanting it anyway, Castiel willed him to open his eyes as his breathing gradually got stronger.

 

The man choked out a cough, the noise stunning Castiel into remembering himself and diving back underneath the water. He swam until he reached the security of the deep, then edged his way back to the air, looking towards the shore.

 

Castiel lingered as the gentle waves lapped his shoulders. He had gone against the creed. Had been warned about breaching the surface, being seen. Histories passed down from the elders, centuries of the cruelties and violence of man. Some would hunt for sport, where the kill would be clean, but the worst kind would destroy bodies to make their own magic. Still he watched, sculling impossibly slowly back to the shore, threading around the rocks as if they would afford protection from dangerous eyes. He waited, unsure as to why, knowing that what he had done contradicted everything that had been instilled in him. Instead of allowing the human to be killed, Castiel had fought for his freedom. He felt a sharp tug on his tail fins and slipped underneath the surf.

 

 _'What are you doing, Castiel? You realise this would count as effectively deserting your post. Again. This is too close to the shore. To them. Do you want to be seen?'_ Balthazar rebuked.

 

Castiel remained unflinchingly silent. Balthazar waited, slightly angling his head to try and catch Castiel's eyes. He could normally coax the truth from his brother, and help to repair any damage his actions caused amongst their clan, but this time he was more disconnected than Balthazar could remember finding him before. Despite his outpost being situated between those of Zachariah and Balthazar, Castiel remained impulsive. He had always been full of purpose, however much it went against orders. Castiel had seemingly developed a habit of going to the surface during the clearest nights. Balthazar had found him studying the sky, looking almost lost to designing an escape in the stars. He had dragged him back underneath to their borderland while trying to warn him that he would one day exhaust everyone's patience and find himself answerable directly to Raphael.

 

_'Castiel. Look at me.'_

 

Nothing.

 

 _'CAS-TI-EL!'_ Balthazar reached for his upper arm in an effort to jolt him into the present.

 

Castiel moved to deflect any contact, but brought his focus to Balthazar, pure bold defiance in his eyes.

 

 _'What did you do? You were seen, weren't you?'_ Balthazar accused.

 

 _'No. I was not seen,'_ Castiel answered simply. He was expecting to be summoned by Zachariah immediately and determined not to compromise Balthazar by making him complicit by association. He hoped they would have a few minutes so he could try to say goodbye and explain that he could not keep his place as part of the clan, but he saw the group of mermen advancing towards them over Balthazar's shoulder. Balthazar turned his head to see what Castiel looked at. Snapping back towards his brother, he pushed his chest. _' Go. Now. Whatever you've done, I'll try to fix. GO!'_

 

Castiel put up no resistance as he was led away on Raphael's orders, Balthazar's shouts echoing through his head.

* 

Sam looked at his brother, grateful he had been found a few hours earlier. After Dean had disappeared, Sam had fought to get to the water but couldn't see his way. Unable to get a steady cell signal, he stumbled back towards the highway until he could call Search and Rescue.

 

Hanging up, his brow creased as his mind raced, trying to think rationally and running through his options. Dean had the keys to the Impala, which meant no supplies for a spell and no transport to get more. He could call someone, try to find anyone was close enough to help. He dialled a few numbers and left messages when they didn't pick up. Winchester wasn't a surname that got you friends.

 

Sam checked his pocket, feeling for the badge he hoped was there. He waited until he saw the search team arrive, then made his way to flag them down and leant in as the car window opened.

 

"Agent Welch, he said, showing his ID. "I'm investigating a case a few towns over and heard someone's missing. I wondered if you guys needed any help?"

 

His offer was met with a nod and he climbed in the back seat. Sam exchanged information with Officer Moran as they headed to the beach. He kept his panic contained as much as he could, focusing on being level-headed and logical. He knew this was currently his only shot at finding Dean, and Sam wanted to make sure he followed the parameters set by the rescue team so as not to endanger anyone else.

 

High tide prevented him from doing as much as Sam needed to do. He was as close to the water as he was permitted by the officers, and repeatedly swept his flashlight across as much of the expanse as he was able. Just before one am, the tide was low enough for Sam to get closer to the rocks. Pushed on by adrenaline, he trudged through the wet sand as quickly as he could, still using his flashlight to scan the water. Sam's frustration at being held back by the search team bit hard. He angled the light to try and see into the cave, but couldn't get close enough to see properly. A search boat had done a sweep earlier of the area earlier and Sam paused, calf-deep in water now, watching as the boat ghosted its shadow on the cave wall. Long minutes passed as he waited for it to come out through the mouth and back into the main stretch.

 

"Agent!" he heard. Sam turned and was met with a light heading towards him. Moran shouted again over the splashes as Sam kicked up the water striding back towards the sand.

 

"We got him."

 

"Alive?" Sam appealed.

 

"Alive," she confirmed.

* 

'Hey" Sam said quietly, pulling the chair closer to the bed. "Can you remember what happened?"

 

Dean looked over at his brother. "I dunno. We were walking to the beach, and ….I dunno, I must have slipped. Something was dragging me down, I blacked out and when I came to, I was on a rock in some cave. I don't remember much else." He paused for a moment, but did not break eye contact. "How long 'till I can get out of here?"

 

"The nurse said it shouldn't be more than a few hours," Sam replied.

 

"Go get a few hours shut-eye and I'll see you later."

 

Sam nodded his acquiescence, pushing the chair back as he stood up to move towards the door. Walking out of the hospital, Sam took his cell from his pocket and dialled the number Moran had given to him before he got in the ambulance with Dean. He promised to give her an update once Dean was up to talking. After four rings, she picked up.

 

"Hello?"

 

"Officer Moran? This is Agent Welch," Sam replied.

 

"Agent! Good to hear from you. How's he doing?"

 

"He's conscious but doesn't remember much about what happened. Said he remembers falling and being pulled down under the water, but then blacked out."

 

"I'm glad to hear he's doing ok. It's been a rough few months."

 

Sam's voice softened. "Is this the first recent report like this in the area?" he asked, already knowing the answer.

 

"Third, actually. I've gotta be honest, part of me hoped you boys would be brought in by now," Moran answered. "But I guess to the Bureau it would just look like people lost at sea," Moran said, exhaling.

 

"You think it's not?" he prompted.

 

"I, I don't know. Everyone grows up with stories about ghosts and monsters. Stay away from the lighthouse at midnight…... don't go into the water, y'know? It's stupid really. But I've lived here my whole life and sometimes I think 'what if?"' she answered. "Some people really believe in stuff like that. It had to come from somewhere. When you can't find an answer that makes sense, you do start to wonder."

 

"What kind of stuff?" Sam asked.

 

Moran hesitated. "It's just….it sounds stupid if you didn't grow up by the ocean, I guess. I mean, are you sure you wanna hear about this? I kinda feel like I'm wasting your time with this, Agent.'

 

Sam gave a small laugh, trying to encourage her to tell him. "I can guarantee that whatever you've got won't be the weirdest thing I've ever heard."

 

She paused for a second then spoke. "Ok. So, years ago there was a fishing boat that went out further than normal. It was a small boat, just a few guys with rods and lines, and their lines kept being pulled and breaking, but there were never any catches. Same thing happened when they went out again and this time one of them leant right over the side of the boat to see if there was anything the lines were getting caught on. He was pulled overboard by a man with a fish's tail. No one ever saw him again and the other guys on the boat never went back out on the water. Story is, they spent the rest of their lives warning people off going out to fish there."

 

"Well," Sam said.

 

"Yeah. Sounds stupid, huh?"

 

"I've heard worse."

 

She laughed and they made their goodbyes, with Moran asking Sam to give her best to Dean.

* 

From his ledge on the tall rocks that jutted up from the clearing on the sea bed, Raphael looked down upon the merman below. Castiel stayed in the small circle of stones and waited. When he had been brought to the garrison for interrogation previously, Zachariah had been in Raphael's place.

 

'Do you know why you are here?' Raphael asked.

 

 _'Yes,'_ Castiel affirmed.

 

_'I want you to tell me.'_

 

_' I saved a creature.'_

 

Silence.

 

_'You saved a monster. You wounded your kin to save a monster.'_

 

Castiel remained defiant, shaking his head almost imperceptibly. _'It was not a threat to us. It was not an attack. They do not attack alone and it did not have a weapon.'_

 

Raphael laughed bitterly. ' _All monsters are threats, Castiel. If they enter our territory, it is an attack. If they try to divide us, it is an attack. If they try to destroy us, it is an attack. Humans do not need weapons to create chaos and cause destruction.'_

 

He gestured to the isolated cluster of caves that stood apart from the corals. Still part of the garrison, they had been etched with symbols of sea magic and fortified with incantations. Castiel looked at the cage that held Lucifer.

 

_'Did you forget?'_

 

 _'No!'_ Castiel insisted as he clenched his fists in frustration. He could never forget.

 

_' Then the act was wilful disobedience. Zachariah has informed me that your attention continues to be easily diverted, Castiel, despite previous warnings. This is troubling, and your actions unacceptable. Zachariah has proven to be a disappointing choice of captain and this leaves me with no choice. You will learn, Castiel, that humans are death.'_

* 

"And what? The….Fin Man dragged me to the bottom of the ocean?" Dean asked, seated on the edge of the motel bed as he finished pulling his boots on. Sam shifted his gaze from the screen and shot him a look.

 

"All I'm saying is what she told me checks out." He angled the laptop for Dean to see. Pausing to take a cursory glance, Dean continued his way around the small table and sat in the chair facing Sam's.

 

"So how do we catch ourselves a fish?" he said, picking up the waiting cup of coffee and taking a sip.

 

"With a net woven of silver," Sam answered, clicking the mouse button.

 

"Huh," Dean shrugged. "And that'll gank it?"

 

"That'll catch it. There's a few ways to kill it. Straight through the heart with a flint blade, or let nature take its course. They can breathe through their skin when out of water, but the amount of time they can survive depends on the amount of trauma suffered."

 

"Trauma? C'mon Sam. These things have feelings now? Rights?"

 

Sam ignored him, reading directly from the screen. "Tail fins of merpeople have been used in spell-work for centuries. Removing the fins is equivalent to an amputation, which will result in death if sufficient care is not taken. One report documents a merman kept alive on land for two years following removal of his fins, and speculates that this could have been increased."

 

Dean pulled out his cell and scrolled through the contacts. Standing up and slowly circling the room while he waited for the other end to pick up, he eye-balled Sam. "I know a guy that has all sorts of crap for the right price."

* 

A few weeks later, having driven for almost three days days each way to Dean's contact and making an unscheduled detour to deal with a buruburu, they checked into a motel about an hour from the beach. Sam guessed that the gum-chewing, unimpressed clerk resting his arm on the front desk was not the same Nicholas whose name was emblazoned in neon lettering on the outside of the building. First into their room now he had the key, Sam opened the the door for Dean as he brought their duffels from the car. He threw one on each double bed and they bickered over who would get to use the bathroom first, as exhaustion cushioned itself deeper between their frayed tempers.

 

The following morning as he wiped the corners of his mouth to remove any bits of stray breakfast burrito, Dean announced that they would be taking a fishing trip.

* 

Lucifer existed to serve as both a deterrent and an example. Every merman knew the history of the fierce warrior that had killed his brother. Sentry over the shore, Gabriel cradled a fascination with humankind and slowly became enamoured with a woman who searched the sand. As defences waned, he learned that she a witch, looking for ingredients for a spell to save her son. Knowing it would mean he would lose his place within the garrison as he would be unable to fight, Gabriel had chosen to help the witch save the boy, cutting off his tail fins. Gabriel tried to ease his reasoning to the other mermen, but Lucifer only heard how his brother had destroyed himself after being infected by humanity. Combined with the fury and fear of what Gabriel's betrayal would lead to, Lucifer had struck his blade into his brother's chest until his heart ceased to beat.

 

The warding on the prison was unbreakable. This was irrefutable. Castiel had ignored Balthazar's pleas for information, only letting him know that Raphael was keeping him at the garrison, but he did not know for how long. Balthazar told him that there had been an increase in activity from the land since Castiel had returned the human, and that Zachariah had increased efforts to strengthen their defences. Being able to talk to Balthazar had been a small spark of warmth. Castiel could hear Lucifer spitting rage and despair, wondering if he registered that he was no longer alone.

 

Castiel tried to quiet his mind, to fight against the fear that he could be responsible for causing another one of his kin to suffer as Lucifer did. He was grateful that the guards treated both prisoners with the same silent contempt. Lucifer recited his liturgy of warnings and admissions to Castiel with increasing desperation. Guilt slowly consumed his resolve. Calling out to Raphael, Castiel confessed that he had been blind to how damaging humankind could be.

* 

"Dude, do you think we should have got the line as well as the net?" Sam nudged, peering over the side into the blue below. The only bites had been rock cod and salmon for the six hours they had been out on the water. Dean scrunched his face as the deck hand approached to tell them they would be heading back within the hour. The boat hire company had made good money charging for full hire even though they were the only passengers on board, but it meant that there had been plenty of time to ask about stories and sightings of anything half-human half-fish. Aside from a retelling of what Sam had already been told, there was nothing new they could add.

 

Disembarking, Dean shot Sam a warning glare when he showed an interest in taking their filleted catch with them. Quickly intervening, Dean told the crew to keep it as thanks, missing the the smirk that flashed over Sam's face as they walked down the wharf towards the parking lot.

 

Back on the road towards the motel, Sam asked what their next move would be. Dean was hesitant in his reply, knowing his brother would try and convince him to find another way.

* 

Castiel would meet with Zachariah whenever it was demanded of him, and again when the sun set to provide a full report of the day's patrol as decreed by Raphael. Zachariah relished every opportunity to remind Castiel of his betrayal. He maintained the facade of being unaffected by the increasing attempts to goad him and repeated to himself that he had to protect his people.

 

After twilight, watches would be taken in turn by two members of the clan, while the others rested. Castiel had been removed from this duty until Raphael had evidence he had earned back the trust of his kin, evidence that he could be trusted before he would be permitted to watch over them whilst they were at their most vulnerable.

 

That night's patrol would be undertaken by Virgil and Balthazar. As he attempted to settle, Castiel's thoughts crept over what the water had given him. Despite himself, he hoped the human was still close and wondered if there was a way to find him. Fighting to suppress the flicker of promise warming his chest, Castiel closed his eyes.

* 

The sun warmed the black foam neoprene of Dean's wetsuit as he dug his toes into the cold sand. He watched the waves lap at the shore as he waited for Sam to finish pulling on his suit. Once he had zipped up, they stashed their bag containing their clothes and headed down to the water's edge.

 

"You've got the net?" Dean asked, squinting as he scanned the horizon.

 

"Yes." Sam answered. He paused for a second and glanced down to Dean's leg holster to check he had the flint knife. "Stay close, ok?."

 

Dean paddled in, instantly wishing it was summer instead. As the water got to waist height, he began to slowly start swimming. Glancing to his right, he saw Sam navigating his way around the rocks. Dean kept moving, getting more used to the temperature. After a few minutes, he stopped to tread water and get his bearings. Taking a deep breath, he dived underneath the water.

* 

Castiel studied the movements of the figure overhead. When it stopped moving, he pushed towards it, using his tail muscles to propel himself upwards. Drawing his knife in preparation, he froze when the human ducked his head and began to swim down, recognising the shape of his silhouette. He remembered the weight of him in his arms and the brush of his hair against Castiel's cheek as he held him. Castiel was sure this was the man he had saved. His human had come back to find him. Slowly putting his weapon away to show he meant no threat, Castiel edged closer. Not getting quite close enough, Castiel followed when he went back up, breaking the surface a few feet away. 

* 

Dean shook the water from his face as he exhaled quickly. He was sure he had seen something before having to come back up for air. Feeling for the knife holstered to his thigh, he tried to shout to Sam to have the net ready, and that he was going to try to herd whatever it was towards him. He regretted not getting the scuba gear but was glad he had more freedom of movement. Taking a few deep breaths, Dean prepared himself to dive back down. He heard a splash and was met with a man returning his stare. He gave him a quick once-over; no gills, no webbing and no fins that he could see. The dark hair and blue eyes looked human enough. Knowing better than to trust anything at face value, he sculled slightly, trying to ease whoever was in front of him towards Sam. If this wasn't their merman, he should probably get him out of the icy water, especially as he didn't seem to be wearing any kind of wetsuit. Dean remained tense and ready to defend, but threw a quick smile to see where it landed.

 

The human slowly orbited around Castiel. Wanting to reach out and show he was no threat, Castiel lifted his hands in the air and tried to communicate telepathically. He got no words but a smile in return. Castiel slowly began to move further into his own territory, trying to encourage him into safer waters. The distance between them increased as he led but was not followed. Again Castiel tried to link to the human but got nothing back. Confused, he tilted his head, searching for answers by altering his view.

 

_'Castiel. I am at the border and I cannot see you. Report now."_

 

Castiel jolted in panic and instinctively flicked his tail, the tips of his fins becoming visible above the water. The human scrambled towards Castiel, knife drawn and ready. He knew he had to answer Zachariah before he began to search to find him, but Castiel could not risk being caught.

 

 _'REPORT,'_ Zachariah persisted.

 

 _'I believed there to be something overhead but I was incorrect and am coming back now,'_ Castiel answered, backing away from the human rapidly, angry at himself for being so foolish and at the man for betraying his hopes.

 

As Castiel darted back under the water, Dean gave chase and tried to pull him back. Castiel spun around to face him, pulling his knife and baring his teeth. Dean lunged forward, blade first, but missed his aim. Castiel threw his arm up to block Dean, the impact of the merman's forearm hitting the human's wrist was enough to loosen his grip. Dean re-tightened his grasp on the handle and tried for a punch with his other arm. Castiel effortlessly avoided any contact, retaliating by hitting Dean hard with the full force of his tail. Disorientated and desperately needing to breathe, Dean tried to get to the surface.

 

Castiel needed to decide quickly whether to wait for another attack or pursue the threat. He would have to fight alone. He could not jeopardize Balthazar by calling him for help and would not admit he needed it from Zachariah. The choice was made for him as Dean furiously kicked his way back towards Castiel. Aiming his entire weight at Dean's stomach, Castiel advanced quickly but braced himself. Dean folded, the impact causing him to drop his knife. Dean was aware it had drifted away and willed himself to think. He had to try and recover quickly and stay calm so he could stay underwater as long as possible. If he had to go up for air he would lose sight of the monster and lack of visual would make him vulnerable. He just had to hold on long enough for Sam. He grabbed out in an attempt to angle Castiel around so they were chest to back, but Castiel had already drawn his blade and caught Dean with a swipe across his palm. Dean ignored the sting, grasping for purchase as he tried to wrestle the knife out of Castiel's hand and knowing he would have to go for air soon. Castiel blocked Dean's punches but could not shake him off. They twisted together in the struggle, Dean feeling weaker but not letting go.

 

Castiel felt the burn of the silver as the net made contact with his torso. Sam had pulled Dean free then pushed him up for air. He hooked the net around Castiel, binding him tighter as he fought. Castiel tried to cut his way out but the flint would not break the strands. He thrashed against the pain, quickly realising that the more he moved the worse it got. He stilled, remembering the other creatures he had seen trapped by men. Castiel tried to calm himself and formulate an escape plan. Sam tugged the net as hard as he could, getting closer to Dean who was coming back towards him.

 

Zachariah watched as Castiel was dragged above the by the two men. He spoke directly to Raphael to tell him Castiel had willingly abandoned his post and his people.

* 

"This is the only son of a bitch that was down there, Sam. Neither of us saw any others so it must be this one." Dean huffed as he pulled the tarp from underneath the weapons stash in the trunk of the Impala. He wedged the bag containing their wetsuits in a corner and turned to face Sam.

 

"It won't talk. It's as much use as canned tuna without an opener and it is NOT going to stink out my baby." He had made no secret of his feelings as they lugged Castiel back to the car. Dean couldn't share Sam's persistence in trying to communicate with the merman to understand why people had gone missing and find out if they were still alive; he just wanted to stop it from happening again. Sam argued that he just needed time to figure it out.

 

Shutting the lid of the trunk, Dean griped about putting what amounted to a huge fucking fish in his car, threatening to skin him alive if there was even a hint of eau de fins on the leather. He covered the back with blue tarpaulin, making sure the floor and the leather were covered while Sam babysat their catch. Castiel had memorised the route back to the water in the desperate hope he would be able to get back there. He bided his time and waited until the humans were speaking. The threads of silver that bound him were too tightly woven to get more than a finger through. He pushed and pulled as he tried to break the net, using his elbows, tail, teeth, anything that he had to but all it did was make the Sam stumble slightly in surprise at the sudden jolt of movement, and then shout out as he tightened his grip. Dean rushed to help him and together they secured the net around Castiel with rope , and hauled him onto the back seat, forcing his tail painfully into the footwell. He let out a broken breath as he realised there was no way he could get free.

 

Castiel remained silent during the miles back to the motel; he knew that Zachariah would immediately report his unaccountable absence to Raphael unless he could get back to the water before sunset, and that he would be banished from ever returning home. This was what he had chosen. He had had gone against everything he had been taught and trusted with. Castiel was the cause of his own destruction. He forced himself to resist calling to Balthazar; he was beyond the help or comfort of his kin now.

* 

It was a struggle to get the merman out of the car and into the small bathtub of the motel room. He didn’t put up much resistance, but there was the constant possibility of someone glancing out of the window at the wrong time. While Sam went to talk to the desk clerk about getting a connecting room, Dean set the cold tap running then walked over to his bed and rifled through his duffel until his hand hit the bag of salt he was feeling for. Back in the bathroom, he upended it in the tub as the water slowly got higher. The merman had been watching Dean guardedly, waiting to see what would happen next. The silver net was still encasing him, biting where it made contact with his body. Dean turned off the tap once the water was deep enough to meet Castiel’s waist.

 

"If it wasn’t for my brother, you would be dead by now," Dean warned, slowly pacing the tiles. Sam stuck his head around the door then stepped into the already cramped bathroom. He stood for a few minutes and quietly watched Castiel focus on Dean, trying to understand his expression. It wasn’t fear or anger, more weary disappointment.

 

Sam decided to speak.

 

"Did you see what happened to my brother? To the other people?" he tried, gently.

 

Castiel switched his gaze from one Winchester to the other.

‘'Hey, asshole, he’s talking to you." Dean hit the bottom corner of the plastic bath panel with his boot.

 

Sam frowned at Dean and asked again. "Do you know what happened to the people in the boats?"

 

Castiel remained still apart from a slight bowing of his head.

 

"Can you tell us?"

 

Castiel pushed against the net, trying to signal he wanted it to be taken off.

 

"No. No way," Dean said.

 

"Tell me what happened and I might take it off," Sam bargained.

 

Castiel gave a soundless sigh and reflexively tried to flick his tail in frustration, angry at what was being asked of him. He had never had to test his speaking voice, and wasn’t even sure he had one to use. He opened his mouth and tried to push the words up and out. The loud croaky bark startled everyone in the room. Castiel immediately clamped his mouth shut, horrified. He was so lost now. There was no way to get through to them. Panic flooded his mind and he raged against his constraints, tired of hurting and thinking and waiting.

 

Sam crouched slightly to try and make himself less intimidating. He waited until Castiel had stopped struggling and tried to encourage him to try speaking again. It took another twenty minutes of coaxing and and a lot of effort on both sides before Castiel could make himself understood. His voice raked over his words, low and deep.

 

"We do not hunt you. You hunt us. Humans enter our waters, taking what they wish and leaving destruction."

 

"The people in the boat….what happened to them?" Sam asked.

 

Castiel curled his lip slightly. "They were not in my territory and I was not called to attack. Our superiors may celebrate every victory but they do not inform us of every decision. The people must keep away. We are not to be hunted."

 

"Celebrate every victory? So you killed them. Those people? They weren’t hunting. They were on a boat, looking for birds. They didn’t have nets or lines or hooks," Dean pressed. "So you just go for anyone. Fisherman or swimmer, they’re all the same to you?"

 

"Are we all the same to you? Not to me. Not before."

 

"Not before what?"

 

"Free me," Castiel demanded, refusing to go further.

 

Dean drew his gun before Sam could speak. "I’m gonna to put you down not let you out."

 

"Woah, WOAH," Sam interjected, pulling Dean back a few steps as Castiel hissed.

 

"So if you’re left alone then you won’t hurt anyone?" Sam checked.

 

"Come on, Sam. How would that ever work? You gonna police the Pacific and make sure no one ever goes in the water again?"

 

"So what do we do, Dean? Get every hunter we know to dive in and take them all out? Start an underwater war?"

 

Castiel gently ran his fingers over his knife without taking his eyes off the humans. He knew that he would not be able to attack them while he was trapped, but should it become necessary, he could use the weapon on himself.

 

Sam turned to Castiel. "Can you tell me why merpeople are hunted?"

 

"Our bodies are ripped apart for human magic. Our tail fins are taken, leaving us unable to swim well enough to fight."

 

"And all the humans you’ve seen; did they try to do this? To you?"

 

Castiel hesitated, tired and hurting. "Not until now. I should have listened. I should have stayed away. I have to protect my people as you have to protect yours."

 

"We aren’t going to use you for magic," Sam reassured him. "Who should you have listened to? Stayed away from where?"

 

"Please, I have told you enough. Cut me from the net.Take me back to the water and I will not come back to the surface again," Castiel begged.

 

Sam saw him turn in on himself, exhausted. He knew the silver must be hurting him, and in order to find a resolution, he would need to be able to bargain. Sam made an offer.

 

"I will undo the net and the rope, and then we’ll talk some more."

 

Dean gaped incredulously at Sam, unbelieving.

 

Sam loosened the rope cautiously, prepared for Castiel to fight. When he was met with no resistance, Sam eased the net off and dropped it by the sink. Castiel was still for a few moments, then stretched out his shoulders and arms, and extended his tail as far as the restrictive tub would let him.

 

"What the hell are you doing?" Dean raged, lunging forward and pulling Castiel’s knife from his waist tie before the merman could react. He shoved it in the back pocket of his jeans, unsure whether Sam placed too much trust in the merman, or if he had genuinely missed it.

 

Dean wanted to put some miles between him and the situation that been building since they found the merman. There was no way this was anything other than crazy. There was no realistic way out of this. Merpeople would keep hunting and humans would keep going out onto the water. It was too big. Too big for them. Sam might try to play the peacekeeper here but it wasn’t going to cut it. He went out into the main room and angrily sat on his bed. He needed a bit of distance but wouldn’t leave Sam without backup; not when they had never dealt with a merman before. Sam left the bathroom door open as he made his way to the kitchenette and grabbed two beers from the fridge. He perched on the edge of his bed and looked at Dean. 

 

"I think everyone could use a break," he said, opening the bottles and offering one to his brother.

* 

When Castiel had been taken inside, the sun had still been in the sky. Through the small bathroom window he could see that it was now the moon’s turn, and he knew that Zachariah should have been calling him to report. It was too quiet, but he felt strangely free. He was tired after talking to the humans, but the net was off and the pain had stopped, leaving just an ache. The humans had moved into another part of their territory and left him. The water was too shallow and the tub too small. Castiel just wanted to be able to swim and calm his thoughts.

 

 _'I can’t find you and Virgil is now doing your patrol. What’s going on?’_ Balthazar asked. Castiel was surprised and relieved to hear his voice. He had been afraid that their connection would be lost completely now that he was on land, and had been trying to get used to the possibility he would never be part of his clan again.

 

 _'I was…. foolish, Balthazar. The human….I saw him again and he had another with him. They took me, and have me now,’_ Castiel confessed.

 

_‘Did they wound you? Are you hurt? Can you get free?’_

 

_‘You can’t help me now, Balthazar. You mustn’t think of me anymore.’_

 

_‘Answer me, Castiel. Are you hurt? Can you get free?’_

 

_‘I don’t know.’_

 

_'What do you mean? You don’t know if they have hurt you or you don’t know if you can get free?’_

 

Castiel was unsure whether to stay silent or tell a guarded truth. _‘I don’t know what will happen, Balthazar. Please, I need you to break from me. I can’t risk you all.’_

 

 _‘We were not your priority before you decided to go after the human.. Now one or all of us are at risk of death because of you, Castiel. Did you learn nothing from Lucifer? Are we not brothers?’_ Balthazar raged. _‘I don’t know how to make this right. I don’t know what to do. I need to think. I need to talk to Raphael, tell him that you were caught trying to defend us. There must be some magic he can use from the ancients.’_

 

 _‘Balthazar. Stop. Whatever happens to me now is my own doing. I’m asking you to let me go. If I can get back I will, but you know I will not be allowed to be with the clan any more.’_ Castiel gathered his strength to make the break from Balthazar. An empty silence filled his head.

* 

"So what now, Sam? What’s your grand plan?" Dean asked, taking a swig.

 

"I…need some time to do some research; I need to find if there is a way to, I don’t know, to broker a deal somehow? I’ve read what little lore there is about mermen but this never really came up. I need to make sure it will work."

 

Dean didn’t ask for more information, trusting he would hear about it when Sam had it clear in his head. "So what’s my job in all this?" he said, waving a hand in the air.

 

"Change his water?" Sam answered, cringing but keeping a straight face.

* 

Dean had been restless since they turned out the lights. He couldn’t relax enough to drift off, even though he realistically knew there was no way for the merman to get out of the tub and kill them in their sleep. After spending a few hours getting more pissed off, he got up, pulled his jeans on and padded to the bathroom that was housing Castiel. Turning on the light, he was pleased to see that Castiel looked as unrested as Dean felt. He sat on the closed toilet seat and stretched his legs out. He slowly moved the flint knife from one hand to the other in warning. Castiel was the first to break the silence.

 

"What do you want?"

 

"Answers."

 

"Then ask."

 

"Those people; they were killed and they didn’t know they weren’t supposed to be there. It wasn’t their fault. They weren’t hunting you, they had no weapons."

 

Castiel waited for him to continue but there was nothing.

 

"What answer can I give you when you have not asked me your question?"

 

Dean stood up and scrubbed his face with his hands. He couldn’t get the words out, it was too much. He pushed them down; it didn’t matter what he remembered. He was alive and that was enough. He silently stalked out to the Impala but didn’t start the engine.

* 

After his morning run, Sam refused to do anything other than read and research. Dean went out to get breakfast, bringing it back to their room. Sam looked up at him as he handed him one of the two bags.

 

"What?" Dean asked.

 

"Where’s his?"

 

"Whose?"

 

Sam tipped his head towards the bathroom.

 

"You have got to be kidding me. There is no way…."

 

Sam frowned. "He has to eat. He’s half human."

 

"No, he’s not. He looks half human."

 

"Dean…"

 

"Fine." he mumbled, poking his head around the door.

 

"You got a name?"

 

"As I told Sam, my name is Castiel. You are Dean."

 

He a mental note to thank his brother for the heads up. "Ok then, Castiel. My brother wants me to get you some food. I know you probably have an extensive choice back home but here it’s whatever I can get, ok?" He flashed a tight smile and turned around, heading back to the table in the kitchenette. He sat down and unwrapped his food, studiously ignoring Sam. When he had finished eating, he balled up the wrapper and silently went back out.

 

Dean stood in line, knowing that doing this made him an asshole but he didn’t really care. He wasn’t sure who he was trying to piss off most, but he had been asked to get food, so food he would get.

 

Sam tensed his jaw in preparation for an argument as Dean put the bag in next to the laptop. "He eats fish, right? This is a fish burger,"

 

Sam ducked his neck slightly and exhaled loudly.

 

"Awww shut up, Sammy. Don’t carp on about it." Dean smirked.

* 

The week continued with Dean being barely co-operative. Sam was getting more frustrated but knew it was pointless to try and make Dean talk about whatever was bubbling underneath. He had been disappearing on longer drives to get supplies but this did little to improve his mood. Eventually Sam snapped, giving Dean a list of things to ask Castiel while he continued working on the laptop, pushing home the point that if Dean wanted the case wrapped up he would do as he was asked.

 

Dean took the piece of paper and went to speak to Castiel. He had made so many visits at Sam’s request It felt like he had worn an invisible path to the bathtub. He had been emptying and refilling the water every morning and evening. Dean had tried to keep their conversations to a minimum, which was easier when there was the sound of running water and the task of trying to wedge a merman out of the way. As he knew he would have to talk to him, Dean took a seat on the closed toilet lid again.

 

"I have a list of stuff Sam needs to know," he began.

 

Castiel looked at Dean and waited for him to speak. There was nowhere he could go and nothing he could do until Sam had what he needed.

 

Dean read from the piece of paper he was holding.

 

"What is the hierarchy of command?"

 

"There were four elders in our stories; the only one that remains in power is Raphael. His second is Zachariah, who was my direct superior. The there are the soldiers, of which I was one."

 

"How many soldiers are there?" Dean asked, deviating from Sam’s scrawl.

 

"Excluding myself, eighteen."

 

Dean focused on the paper again. "Is there anything other than tail fins that are used for spells?"

 

"It is difficult to know, Dean. The other mermen, the ones that are taken, they do not usually return."

 

"Usually? So they can return unusually?"

 

Castiel told Dean the history of Gabriel and Lucifer, omitting all details of his own experiences.

 

"Would the other mermen see you as one of the taken now?"

 

"Yes," Castiel said, quietly.

 

"Were you there, in the water, when I fell?" Dean blurted, not taking his eyes from Castiel’s.

 

Without pause, he replied, "Yes."

 

"You rescued me."

 

Castiel did not need to answer.

 

"Why’d you do it?" Dean almost whispered. "I’m not one of you."

 

"You were fighting to be free. For your life. Humans don’t hunt alone, and you were unarmed. Your destruction was something I could not allow. I couldn’t look away and know I had let it happen. You were not a threat to us then, Dean. Are you a threat to me now?"

 

He backed away, unsure of how to answer. Dazed, he dropped Sam’s list of questions on the keyboard of the laptop as he went outside.

* 

Balthazar had not fully ceased his attempts to contact Castiel. He could hear him, like a faint echo that he had to focus to tune out. It was only when he increased his persistence to panic levels that Castiel let him in.

 

_‘Why didn’t you answer me? I started to think I had lost you. Are you alright?’_

 

 _‘Yes. Are you?’_ Castiel replied gently, ignoring his fading scales and aching muscles.

 

Balthazar gave a snort of derision. _'I’m fine. Zachariah, however, has been making it his priority to relay what he is calling your ‘mutiny’. Weapons are constantly raised, Castiel. He is preparing us for the end battle.’_

 

Guilt washed over him. Castiel thought about trying to reach Zachariah or Raphael to explain, but until he knew what Sam would find, he could not make any bargains, even if they would listen to him.

 

_‘Balthazar…..I’m sorry.’_

 

_‘I know. As am I.’_

 

_‘I will put this right somehow.’_

 

_I wish for that to be true.’_

* 

"Cas, you need to help us with this one," Sam said. "More people are disappearing, and it’s not just in this area. Is there some kind of network with other clans? Maybe the elders speak to each other, to share warnings or information?"

 

"I...I don’t know for certain. I have never had to contact a merman outside of my clan but being able to communicate with other groups would be beneficial against a significantly advanced threat." 

 

"Is this about the call you got this morning?" Dean asked Sam.

 

"Yeah. It was someone I left a message with when you went missing; they said they should have known not to trust a Winchester, and that they would be getting rid of the problem."

 

"Well, who was it?" 

 

"No-one we really know. Greg Calderston…."

 

"From the salt and burn in Lanham….yeah, I remember. Why did you even call him, Sam? Who does he think he’s going to be taking out? Us or them?"

* 

They took extra precautions over the next few days but nothing really changed; it seemed too quiet after the phonecall, and Dean was uneasy. They continued the pattern they had created; Sam worked to pull together what he needed, promising Dean it wouldn’t be more than a few days until he was ready. Dean sandwiched supply runs between learning Castiel and picking up strands of lore that Sam needed to tie up. Sam had also been monitoring missing person reports; due to the time of year the beaches were relatively empty, but the number of people reported lost at sea had increased based on the statistics for the previous years.

 

Castiel spoke to Balthazar to ask him if attacks had become more frequent. Balthazar confided that Zachariah’s zealotry had escalated, pushing their boundaries further and giving orders to destroy everything that breached the borders they now guarded.

 

Sam closed the laptop screen and told Dean he was sure he had everything he needed, and it was time to try and speak with Raphael. Castiel had told them that while he could attempt to reach Raphael telepathically, their best chance for their plan to work would be for Castiel to return to the garrison; to prove to Raphael that he was alone and unharmed. There was no argument against this. They checked out of the motel, agreeing to stop at different one if they had to stay another night. Castiel was stretched out as much as he could be on the back seat, trying to prepare himself for what would he would be called to do.

 

They had expected the beach to be deserted due to the cold weather and rain. The cluster of three men grouped by the water’s edge signalled trouble. Dean told Sam to hang back in the cover of the rocks with Castiel while he jogged ahead. As he curved in on them, he could see a tangle of arms and tails enmeshed in silver netting. 

 

"Hey, what’re you doin’?" Dean shouted.

 

All turned round but only one answered. "Dean Winchester. It’s been a while. I gotta say I’m surprised to see you. I got your brother’s message and when the body count started going up again I thought little Sam couldn’t handle it on his own, so brought some of my boys to take care of the problem."

 

"Oh I’m just peachy, Greg, and we’ve got this. We don’t need back up."

 

"Ah, here comes the cavalry," Greg sneered.

 

"Let them go," Sam said as he got closer.

 

"They’re monsters, we’re hunters. I’m not letting them go. Have you lost your damn mind?"

 

"It’s not what you think….there’s more to it than just monsters killing people."

 

"There’s always a sob story if you wait long enough. I see you’ve got one of your own," Greg said, gesturing to towards the pool that Castiel had moved to. "And I’m not in the mood for listening."

 

He pulled his gun and aimed it at Castiel. Before he could take a shot, Dean threw himself at Greg, wrestling the gun from him. Greg’s buddies pulled their shotguns and trained them on Sam. He raised his hands to show he was unarmed.

 

"I can stop this," Sam pleaded. "I can stop this without anyone else getting hurt."

 

"Talk," Greg barked.

 

"The reason people are dying; it’s because the mermen are killed for their tail fins. They’re hunting us because we hunt them. We’ve done the tests and checked the lore. A merman’s scales can be used instead of his fins for a spell. Their magical values are almost interchangeable; you need more of the scales, but they can grow them back. "

 

"How does this save anyone? You tested it with one willing subject; what about the rest? You can’t guarantee that the other bastards will honor anything."

 

"Cas said he will be able to make a deal with the chiefs. He’s given us no reason to doubt him." Dean argued.

 

"And you expect us to go along with this love-in because why?"

 

"Because he’s going to bat for us, and it’s everyone’s best shot."

 

"You’ve got an insurance policy if this all goes to hell?"

 

"Rip the sons of bitches apart."

 

Greg chewed on the lie that Dean fed him. "I want to talk to this Cas myself. That alright?"

 

Guns were lowered in an uneasy truce and the Dean led the group of hunters across the sand towards the pool where Castiel was sculling in wait. They formed an uneven line as Castiel looked to Dean for a signal that that it was safe to come closer. Dean motioned to him to come forward, and Castiel approached.

 

"So he’s trusting you to end this mess?" Greg asked.

 

"Yes." Castiel answered.

 

"I don’t think so." Greg lunged.

* 

Castiel felt the heat flood through his body as the flint burst into his heart. He was unable to answer the call of his name as his breathing ebbed and the waves carried him home. 


End file.
